1. Field of the Invention
The present invention relates generally to a luggage cart having a telescoping handle and fixed wheels located at the bottom of the luggage cart.
2. Description of the Prior Art
Conventional luggage carts having telescoping handles and fixed wheels are well known for conveniently transporting personal items when the user is traveling. The carts reduce the burden of transporting the weight of the personal items during transportation. One example of a prior art luggage cart is disclosed in U.S. Pat. No. 5,951,037 to Hsich.
Physically, the reduction of the load of the weight of the luggage cart is governed by the principle of leverage. A level of comfort to enable reduction of the load that the user can achieve is dependent upon how the user applies the physical principles of leverage based on the physical condition and body height of the user.
It is also well known that achieving a level of comfort by using a conventional luggage cart is limited, since complete reduction of the load of the luggage weight is very difficult to achieve. This is due to that fact that complete reduction of the load to a user from the luggage weight can only be achieved when the telescoping handle is raised high enough so that a particular large angle is reached, which is defined by the luggage body relative to the ground. In that orientation, the center of gravity of the luggage weight is perpendicular above the center of the wheels. At this particular position, the law of leverage permits the user to have zero load from the luggage weight.
However, it is also well known that the particular position is physically very unstable since the position of center of gravity of the luggage weight is higher than that of a support point where the wheels contact the ground. In addition to the instability, it is also difficult for the user to pull the luggage cart in this orientation when there is the large angle relative to the pulling direction.
To compensate for and overcome such difficulties, the user usually will lower the telescoping handles in order to exchange stability as a tradeoff in order to make pulling the luggage cart easier. However, as a result, if the user has to travel a long distance with the luggage cart, the burden on the user will be increased. This problem will be worsened if the user is elderly or physically weak, or is carrying other items, or is carrying a baby.
Many inventors have tried to improve the comfort to users by utilizing a luggage cart. One such inventor is Miles. The Miles invention shown in U.S. Pat. No. 6,464,245 discloses an improvement in handle design by adding a secondary grip extension. However, the invention does not solve the problem disclosed above.
There is a significant need to significantly reduce the load of the luggage weight as a luggage cart is being pulled.